Apparatus for and method of testing cords



Dec. 16, l930. 1'. B. BuFFuM APPARATUS FOR AND METHOD OF TEST-ING GORDS Filed March 29, 1925 f ATTORNEY Patented Dec. 16, 1930 UNITED STATES PATENT OFFICE THOMAS r. BUrrUM, or AxnoN, omo, AssIGN'on 'ro 'ran eoonmnlrm a RUBBER COMPANY, 01E-AKRON, OHIO,` A CORPORATION OF OHIO APPARATUS FOR AND METHOD OF TESTING COBDB application nieu nani 2s, 192s.' serial No. 628,611.

My invention relates to a machine for and a method of testing cords, such as are utilized in the construction of pneumatic tire carcasses, and it has, for its primary object, the

'provision of a machine of the above designated character, which may be employed to approximately establish conditions of test that the cords are subjected to in a tire during its operation.

The majority of pneumatic tires now manufactured are of the type generally called cord tires, which embody cord fabric. The cords embodied in such fabric are, of course, made from materials which are not uniform and, consequently, it is desirable to provide a test whereby the cords may be tested for durability under conditions approximately those attending their.use. The primary object of this invention resides in testing cords in such manner as to indicate their qualities and whether they possess the desired characteristics necessary for service in pneumatic tires. v

The'various objects and advantages of my invention will be apparent from the following description read in conjunction with the accompanying drawings.

n In the drawings: ,Figsflis a plan view of apparatus conaccordanceA vwith my invention "that is adapted `to test the durability of cords Fig. 2 is alsideelevational` view of the apparatus shown in Fig. 1; and

Flg. 3 is a plan view of apparatus` similar to vthat shown in Fig. 1 with the addition of a heating device adapted to apply4 heat to the cords under test.

In practicing my invention a. machine may be provided for testing cords by mounting a pulley upon a supporting-plate, to which is suitably connected ya slidably mounted member provided with a plurality of hooks or other fastening means to. which y the ends of a cord may be attached. A roller bearing is disposed in proximity to the slidable member, and another reciprocable member ismounted upon the plate, which is provided `with a highly polished roller bearing. Means -may be provided for attaching a weight to the last mentioned lreciprocable member. A cord may be mounted upon the roller bearings and attached to the slidable member whereby movement of the slidable member imparts movement to the cord, thus flexing it in somewhat the same manner as occurs when such a cord is embodied in a pneu- 2 having drive pulleys 3 secured thereto.

An-auxiliary drive shaft 4. is mounted upon the plate 1 and has a Pulley 5 rigidly secured in contiguous relation upon one end thereo to an idler pulley 6. A belt 7 is trained over the drive pulley 3 and either the idler pulley 6 or the drive pulley 5, depending upon whether the machine is being operated. A driven disc 8 is mounted upon the other end of the shaft ltand is provided with a central slot 9, having angular Walls,l into which is fitted anelongate bar 10 carrying a crank pin 11.- A connecting rod 12 is secured to the crank pinl 11 and to a stud 13 mounted upon a slidable member 14, which is also mounted upon the plate 1. A member 15 is rotatably mounted upon the plate 1 and is preferably formed of hardened metal 'provided with a highly polished surface to reduce the possi-l the plate 1 andcomprises a supporting base 17 provided with a plurality of channels 18 adapted to receive roller bearings 19, to which a plurality of barsl 20 are secured. A cylindrical member 21 is rotatably mounted between the bars 20 and is formed of hard- 'ened steel provided with a highly olished surface so that it resembles a roller caring. A pin 22 'is secured to the movable bars 20 to provide for attaching a weight 23 thereto by means of a cable 24 passed over a pulley 25 mounted upon the end of the plate 1.I

In operating the machine or device above described, a test cord 26 is trained about the the roller bearings or rotatable members 15` and'21, and securedto ins upon the member 14. It willbe. appreciated that the cord is thus held in a definite position and prevented from rotating when given arecipocable movement or a movement in the direction of-its longitudinal axis. The drive shaft 2 may be continuously operated and the remaining portions of the device maintained stationary by training the belt 7 over the idler pulley 6. When it is desired to begin a test, the belt is then moved to the drive pulley 5, which, consequently, drives the disc 8, thereby eilecting a reciprocable movement of the member 14. The extent of this movement is controlled by the position of the bar 10 and the crank pin 11, because, obviously, the throw of the crank arm depends upon the eccentricity of its mounting.

As the member 14 is moved to and fro upon its mounting the cord will be moved over the members 21 and 15, while the weight 23 constantly imposes a load thereupon regardless of the anount of stretch lthat results in the cord. It shouldbe noted that the rotatable member 15 is of somewhat greater diameter thanthe member 21, and, consequently, the iexing action of the cord 26, resulting from its movement over the rotatable members, is greater adjacent the member 21 than the member 15. Consequently, breakage always occurs in the cord near the member 21 rather than its cooperating member 15. The continued and periodical flexing of the cord,

which is under tension resulting from the imtion, and 1n such application of t position of -the weight 23 thereupon, very closely approximates conditions that exist in a tire carcass because the cords are continually iiexed and subjected to tensionI due to the lload imposed thereupon. Moreover, there is practica ly no wear as a result of friction because of the nature of the rotatable members 15 and 21. f

It will be obvious that anumber of units, such as shown in Figs. 1 and 2, may be mounted in alignment to facilitate concurrent tests of a number of cords. However, the unit described and shown in Figs. 1 and 2 constitutes an embodiment of the invention. It will be observed, furthermore, that the supporting plates may be mounted in an uplright posie machine, the weight 23 will, of course, be suspended -in a direct line therefrom. However, such minor features of the construction and applicationof the machine do not alter the principle involvedin its construction and adaptation. j

In Fig. Sis shown a plurality of units, such as shown in Figs. 1 and 2, but with the addition of a heating device comprising a cham-v ber 27. The chamber 27 is provided with a cover 28 and a pluralityA of openings 29 ,maintaining the cords under test at a temthe chamber 27 encloses 'the reciprocable l.

member 21 in order that heat may be supplied to that portion of the cord which is subjected to the breakage test. Suitable conduits 30 are connected to a source of heat supply, not shown. The addition of the heating device to the apparatus provides -for perature approximating the temperature attained in a pneumatic tire when being continuously driven under the application of a load. With the addition of the heating device, a very close approximation of the conditions existing in a pneumatic tire are established, and, consequently, comparative tests may be run upon various cords to determine their ability to withstand the stresses limposed upon them in a tire carcass. It has been found by testing a certain `type of cords and subsequently embodying cords of this type in a tire, that very close comparisons may be made for determining the value of the material.

Although I have shown and described apparatus that may be constructed in accordance with my invention and set forth a l 1method of testing cords by the operation of such apparatus, it is obvious that many changes may Abelmade in the construction of the -apparatus and in the method of utilizing it without departing from the spirit or scope of my invention, and I desire, therefore, that no limitations shall be imposed, except such as are indicated in the appended claims.

What I claim is:

1. A cord testing device comprising means for imposing a load upon and for securing a cord against rotative movement about its own axis, including members about which the cordis looped, said means also including a member connecting the ends of the'cord adjacent'each other, and means acting upon the last named member for flexing the cord.

2. A cord testing device comprising means for imposing a load upon and for securing'a cord against rotative movement about its own axis,including a reciprocable member securing the ends of the cord adjacent each other, and means associated with the reciprocable member for flexing the cord.'

3. A cord testing device comprising a reciprocable member, means for securing the vends of a cord thereto, a plurality of rotatable members around which the cord may be l A Y for flexmg a cor "stant load upon the cord an the members until it securing a cord in a substantiall1 ciprocable member,

ends of a cord thereto, a plurality of rotatable l bers to form a loop, connecting -eating the first member, means for impos' a constant'load upon the cord. 5. cord testingdevlce comprising a remeans for securing the members of un ual size one .of which is mounted upon aei reciprocating the first mem r; and means for securing a load upon theslidable support.

6. A cord testin device comprising means means surroundmg the cord for applying heat thereto, and means for imposing a constant' load upon the cord.

A cord' testing device comprising a reciprocable member, means `for varyin the degrec of movement of the member, a pglurality of rotatable members of unequal sizel about which a cord may be trained, means for securing the ends of the cord to the first member,

means for effecting .a reciprocating moveand means for 1mv the cord adjacent each other,im

moving the cord in 9. A method of testing cords that comprises loop about two separated revo uble spools,

`connecting its ends to a reci rocatin mem-- ber, imposing a constant loa u on t e cord through one of the spools, an alternately moving the cord in opposite directions about the ls clgrdbreaks.

In witness whereof, I have hereunto Vsigned my name'.

vTHOMAS B. BUFFUM by reciprocating the member until dable suplpeort, means for continuous 

